1. Field of the Invention
The present invention relates to a semiconductor device manufacturing line, and more particularly to a semiconductor device manufacturing line in which a semiconductor wafer is accommodated in a carrier and transferred between steps.
2. Description of the Background Art
A semiconductor integrated circuit is formed by successively performing a film deposition process, a photolithography process, a processing process and the like on a semiconductor wafer using a variety of semiconductor facilities in a semiconductor device manufacturing line.
The semiconductor manufacturing facilities include a semiconductor manufacturing apparatus substantially processing a semiconductor wafer in each step, a check apparatus determining whether the processing by the semiconductor manufacturing apparatus is appropriate, a transfer apparatus transferring a carrier which accommodates a semiconductor wafer, a stocker storing the carrier and the like.
In the semiconductor device manufacturing line, the operation of each semiconductor manufacturing facility is executed by a program that is built in a host computer in advance. Under the control of this program, the semiconductor wafer is accommodated in a prescribed carrier and transferred between process steps.
The method of operating the semiconductor manufacturing facility includes, for example, three operations: a wafer applying operation; a wafer manufacturing operation; and a wafer completing operation. A substantial operation for forming a semiconductor integrated circuit on a semiconductor wafer is carried out through the wafer manufacturing operation.
A rework processing operation and a carrier exchanging operation will be described as an exemplary wafer manufacturing operation.
First, the rework processing operation will be described. The rework processing operation refers to an operation in which when the processing performed on a semiconductor wafer by the semiconductor manufacturing apparatus is failed (out of specification) as a result of a prescribed check apparatus checking, that semiconductor wafer is restored to a state prior to that processing and the same processing is then performed on that semiconductor wafer again.
FIG. 21 shows a bay 119 at one step. Bay 119 is provided with four manufacturing apparatuses 110a-110d, one check apparatus 116, a wafer transport apparatus 148, a manual rack 149, an intra-bay transfer apparatus 120, and a stocker 121. It is noted that manual rack 149 stores a carrier. Stocker 121 is connected to intra-bay transfer apparatus 120 and an inter-bay transfer apparatus 122.
A rework operation is performed based on a check result of check apparatus 116. As shown in FIG. 22, the conventional check apparatus 116 is provided with a load port 111 receiving the carrier in which a semiconductor wafer is accommodated, similar to semiconductor manufacturing apparatus 110. Here, two load ports 111, that is, a left load port 111a and a right load port 111b are provided for performing successive processing.
A reader 112 for reading a carrier ID is attached to each load port 111. When a carrier is transferred to load port 111, reader 112 reads the carrier ID to identify that carrier ID with the instruction from host computer 114.
Load port 111 is also provided with an opening/closing mechanism (not shown) for opening and closing a carrier door of the carrier. Furthermore, check apparatus 116 is provided with a carrier movement communication interface 113 and a control carrier communication interface 115.
Carrier movement communication interface 113 indicates that a carrier is externally applied or ejected. Control communication interface 115 communicates semiconductor wafer processing information and the like with host computer 114.
The conventional check apparatus 116 is provided with a failure load port 117. This failure load port 117 is a port arranged for externally delivering a dedicated carrier into which a semiconductor wafer determined to be failed through the check is ejected (referred to as xe2x80x9cNG carrierxe2x80x9d hereinafter). It is noted that the semiconductor wafer determined to be passed is returned to the carrier placed on the original load port 111.
In the rework operation, intra-bay transfer apparatus 120 connects semiconductor manufacturing apparatus 110, check apparatus 116 and stocker 121 for transferring the carrier.
However, NG carrier is transferred by an operator 147 to wafer transport apparatus 148, manual rack 149 and stocker 121.
The carrier flow will now be described. Under the instruction of the host computer (not shown), as shown in FIG. 21, the carrier accommodating a semiconductor wafer for which processing is completed in semiconductor manufacturing apparatus 110b (operation pk27) is transferred by intra-bay transfer apparatus 120 from load port 111 of semiconductor manufacturing apparatus 110b to load port 111 of check apparatus 116 (operation pk28).
Check apparatus 116 checks a product wafer accommodated in the carrier to determine it is passed or failed as to whether the processing by semiconductor manufacturing apparatus 110 is properly performed. The product wafer determined as being passed is returned to the original carrier. On the other hand, the product wafers determined as being failed are collected by operator 147 into NG carrier arranged at failure load port 117 (operation pk29).
After all product wafers have been checked, the carrier that accommodates the product wafer determined as being passed (referred to as xe2x80x9cparent lotxe2x80x9d hereinafter) is transferred by intra-bay transfer apparatus 120 to intra-bay application port 139 (operation pk30). This parent lot is conveyed from intra-bay application port 139 to a shelf 134 of stocker 121 by a crane 133 and is accommodated in stocker 121 (operation pk30x).
Meanwhile, NG carrier is removed from failure load port 117 of check apparatus 116, transferred to manual rack 149 by operator 147 (operation pk31) and stored there temporarily.
Under the instruction of the host computer, the parent lot accommodated in stocker 121 is ejected to manual ejection port 136 (operation pk32). The parent lot ejected to manual ejection port 136 is transferred to manual rack 149 (operation pk33). Then, NG carrier is matched with the parent lot.
Then, NG carrier is regarded as a rework lot by operator 147 through the host computer, and the rework processing for the accommodated product wafer is started. First, as shown in FIG. 23, the rework lot on manual rack 149 is transferred to manual application port 135 of stocker 121 (operation pk34).
The rework lot transferred to manual application port 135 is once accommodated in stocker 121 (operation pk35). The rework lot accommodated in stocker 121 is subjected to the rework processing through the wafer manufacturing operation in accordance with manufacturing standard information for rework, held by the host computer.
The rework lot accommodated in stocker 121 is then transferred by inter-bay transfer apparatus 122 to the next step (operation pk36). As shown in FIG. 24, the rework lot transferred to the next step is then transferred by inter-bay transfer apparatus 122 and accommodated in stocker 121 in accordance with the wafer manufacturing operation under the instruction of the host computer (operation pk37).
In response to the demand, for example, from manufacturing apparatus 110b in the next step, the rework lot is ejected to intra-bay ejection port 140 (operation pk38). The rework lot on intra-bay ejection port 140 is transferred to load port 111 of manufacturing apparatus 110b by intra-bay transfer apparatus 120 (operation pk39). Manufacturing apparatus 110b processes the rework lot (operation pk40).
The rework lot for which manufacturing apparatus 110b completes the processing is transferred from load port 111 to the load port of check apparatus 116 (operation pk41). In check apparatus 116, the product wafer in the transferred rework lot is checked (operation pk41x).
The rework lot in which the check for all product wafers is completed is transferred from load port 111 to intra-bay application port 139 of stocker 121 (operation pk42). Thereafter, the rework lot is accommodated from intra-bay application port 139 into stocker 121 (operation pk43).
As shown in FIG. 25, the rework lot accommodated in stocker 121 is then ejected to manual ejection port 136 under the instruction of the host computer (operation pk44). The ejected rework lot is transferred by operator 147 from manual ejection port 136 to manual rack 149 (operation pk45).
After operator 147 confirms that all the rework processing for the product wafer in the rework lot has been completed, operator 147 transfers the parent lot thereof from manual rack 149 to load port 111b of wafer transport apparatus 148 (operation pk47).
The rework lot is also transferred from manual rack 149 to load port 111b of wafer transport apparatus 148 (operation pk46). Wafer transport apparatus 148 then transports the product wafer in the rework lot into the carrier of the parent lot (operation pk48).
Then, as shown in FIG. 26, the parent lot in which the transfer of the product wafer is completed is transferred to manual application port 135 of stocker 121 by operator 147 (operation pk49). The carrier transferred to manual application port 135 is once accommodated in stocker 121 (operation pk50).
Thereafter based on the manufacturing standard information for that carrier, held by the host computer, the semiconductor manufacturing apparatus that will process the product wafer next is decided and the carrier is transferred to the nearest stocker 121 in the next step by inter-bay transfer apparatus 122 (operation pk51). A series of the rework processing operations is thus completed.
It is noted that after the carrier that has accommodated the product wafer determined as being failed is temporarily stored by operator 147, it is again returned to failure load port 117 of check apparatus 116 for use in the rework processing (operation pk52).
The conventional rework processing operation using the host computer as described above can be divided into processing for the parent lot and processing for the rework lot. As described above, in the parent lot, the product wafer formed in the wafer applying operation is accommodated in one carrier.
On the other hand, in the rework lot, the product wafer separated from the parent lot is accommodated in one carrier as being determined as being failed by the check apparatus after a prescribed semiconductor manufacturing apparatus performs prescribed processing.
First, as shown in FIG. 27, the rework processing for the parent lot is started when the processing performed by manufacturing apparatus 110 is completed and that processing is checked (step ps1). Then, the parent lot is checked by check apparatus 116 (step ps2). If all product wafers are passed, all the product wafers are accommodated in the original carrier, and a series of processing is completed (step ps4).
If even a single product wafer is failed at step ps2, however, the processing for the parent lot is temporarily suspended as shown in step ps3. In this case, the failed product wafer is temporarily stored in stocker 121, waiting for the determination of operator 147.
Next, as shown in FIG. 28, the processing for the rework lot is started upon operator 147 determining the failed product wafer (step ps5). Then, the rework lot which corresponds to the parent lot and is recognized by the host computer is formed (step ps6). The rework processing for the rework lot is then carried out (step ps7). After the completion report from operator 147, the completion processing for the rework lot is carried out (step ps8). A series of rework lot processing is thus completed (step ps9).
After the processing for the rework lot is completed, that product wafer is transported by wafer transport apparatus 148 to the carrier of the parent lot of which processing has been suspended temporarily, and all product wafers 2a are gathered. Thereafter operator 147 lifts the suspension of operation progress, and a series of operations is completed (step ps4).
The conventional rework processing operation has been carried out in the manner described above.
The conventional carrier exchanging operation will now be described. FIGS. 29 and 30 show a built-in type wafer transport apparatus 141 for use in the carrier exchanging operation, along with stocker 121.
Built-in type wafer transport apparatus 141 is provided with crane load ports 143a and 143b at a position relative to load ports 11a and 111b of wafer transport apparatus 148, and crane 133 of stocker 121 delivers the carrier.
It is noted that wafer transport apparatus 148 is provided with a filter-fan unit FFU 142 for keeping cleaness of the environment in which the product wafer is handled, a carrier door opening/closing mechanism 144 opening and closing the door of the carrier, and a wafer transferring robot 145.
Wafer transferring robot 145 is used to pick up a particular semiconductor wafer from the carrier and transfer it to a different carrier. Wafer transferring robot 145 is equipped with a device reading a wafer ID. It is noted that stocker 121 having built-in wafer transport apparatus 141 is called a hybrid stocker 121a as one kind of stocker 121.
FIG. 31 shows a bay 119 in one step. Bay 119 is arranged with four manufacturing apparatuses 110a-110d, intra-bay transfer apparatus 120 and inter-bay transfer apparatus 122, in addition to built-in type wafer transport apparatus 141 and hybrid stocker 121a as described above. Hybrid stocker 121a in this bay 119 is connected to a stocker in another bay through inter-bay transfer apparatus 122.
As shown in FIG. 31, the processing of a product wafer by semiconductor manufacturing apparatus 110 is completed in accordance with the step control operation of the wafer manufacturing operation (operation pk53). The host computer (not shown) refers to the manufacturing standard information of this product wafer, and an exchange flag in the next step is examined.
If the exchange flag is ON (to be exchanged), the carrier exchanging operation is started. On the other hand, if the exchange flag is OFF (not to be exchanged), the step control operation continues.
When the carrier exchanging operation is started, as a series of operations for receiving a carrier in the nearest hybrid stocker 121a, first of all, a carrier is transferred from semiconductor manufacturing apparatus 110b to intra-bay application port 139 of stocker 121 (operation pk54). The carrier transferred to intra-bay application port 139 is once accommodated in hybrid stocker 121a (operation pk55).
The carrier once accommodated is placed at crane load port 143b of built-in type wafer transport apparatus 141 from shelf 134 by crane 133 (operation pk56). An empty carrier which is stored in hybrid stocker 121a in advance is placed from shelf 134 to crane load port 143a by crane 133 (operation pk57).
Then, the product wafer in the carrier placed at crane load port 143b is transported into the empty carrier placed at crane load port 143a, by built-in type wafer transport apparatus 141 under the instruction of the host computer (operation pk58).
Then, as shown in FIG. 32, after the operation of transporting the product wafer is completed, the emptied carrier is once accommodated in hybrid stocker 121a (operation pk59). On the other hand, the carrier that has accommodated the product wafer is also once accommodated in hybrid stocker 121a (operation pk60).
The carrier that has accommodated the product wafer is transferred by inter-bay transfer apparatus 122 to a bay in which the processing for the next step (operation pk61), and the next wafer step starting operation continues.
On the other hand, the emptied carrier is cleaned for the next carrier exchanging operation under the control of the host computer. A series of carrier exchanging operations is thus completed.
The conventional carrier exchanging operation described above will be described using a block diagram. As shown in FIG. 33, first, each carrier is registered in the host computer and enters a carrier control state pb1, for use in the semiconductor device manufacturing line.
The carrier in carrier control state pb1 is unconditionally brought into an uncleaned empty carrier state pb4 (state transition pta). The carrier in uncleaned state pb4 is cleaned by a carrier cleaning apparatus (not shown) under the control of the host computer and then enters a cleaned empty carrier state pb2 (state transition pt3).
Any empty carrier in cleaned empty carrier state pb2 is selected when an empty carrier to be exchanged is required, before the carrier that is emptied through the carrier exchanging operation is transferred from shelf 134 of hybrid stocker 121a to crane load port 143a of built-in type wafer transport apparatus 141 as shown in FIG. 31 (operation pk57).
The selected empty carrier is transferred from shelf 134 of hybrid stocker 121a to crane load port 143a of built-in type wafer transport apparatus 141 (operation pk57) for use in the carrier exchanging operation.
When a product wafer is transported into that empty carrier by built-in type wafer transport apparatus 141 (operation pk58), as shown in FIG. 33, that carrier accommodates the product wafer and enters a filled carrier state pb3 (state transition pt1).
When the carrier in filled carrier state pb3 is emptied through the carrier exchanging operation, it unconditionally enters uncleaned empty carrier state pb4 (state transition pt2). The empty carrier in uncleaned empty carrier state pb4 is cleaned by the carrier cleaning apparatus under the control of the host computer and enters cleaned empty carrier state pb2 (state transition pt3).
In this way, each carrier is repeatedly used based on the carrier exchanging operation. The conventional carrier exchanging operation has been carried out as described above.
As described above, the product wafer is accommodated in a prescribed carrier and transferred between steps in the semiconductor manufacturing line. The conventional semiconductor manufacturing line, however, has the following problems in transferring or handling a carrier in this manner.
First, in the rework operation in the conventional semiconductor device manufacturing line, as described above, the product wafer that has been processed by each semiconductor manufacturing apparatus is determined by a prescribed check apparatus 116 as to whether that processing is properly performed. The product wafer on which the processing is not performed properly is distinguished as a failed product wafer from a passed product wafer on which the processing is properly performed.
The product wafer determined as being failed is accommodated in a prescribed NG carrier placed at failure load port 117 of check apparatus 116. In order to perform the rework processing on that product wafer determined as being failed, a rework lot is formed for the NG carrier accommodating the failed product wafer. The failed product wafer is transferred to a prescribed corresponding semiconductor manufacturing apparatus and the like for prescribed rework processing.
At this point, it has been necessary for the operator to manually create a database for the rework lot for the host computer in advance. Therefore it is not possible to carry out the rework processing timely, and the production period of the semiconductor device becomes longer.
In the carrier exchanging operation in the conventional semiconductor device manufacturing line, as described above, a carrier is used immediately after being cleaned, as an empty carrier required for exchange.
Therefore, each time a carrier is emptied through the carrier exchanging operation, that emptied carrier is transferred to a prescribed cleaning apparatus for cleaning.
As a result, the frequent transfer of the emptied carrier adversely affects the transfer of the carrier accommodating a product wafer, and a smooth transfer may be interrupted. Moreover, the costs for cleaning carriers and securing an appropriate number of carriers are inevitably increased. In addition, a space for storing the carriers is necessary.
An object of the present invention is to provide a semiconductor device manufacturing line to address the aforementioned problems in transferring or handling a carrier accommodating a product wafer.
According to one aspect of the present invention, a semiconductor device manufacturing line for manufacturing a semiconductor device using a container accommodating a semiconductor wafer includes a manufacturing apparatus, a check apparatus, one container and another container, a wafer transport apparatus, a storage apparatus, a transfer apparatus, and a control apparatus. The manufacturing apparatus performs prescribed processing on the semiconductor wafer. The check apparatus checks whether the processing performed on the semiconductor wafer by the manufacturing apparatus is appropriate. One container and another container respectively accommodate a prescribed number of semiconductor wafers. The wafer transport apparatus has a function of taking a prescribed semiconductor wafer determined as not being processed appropriately and requiring rework processing out of a prescribed number of semiconductor wafers checked by the check apparatus and accommodated in one container for transporting from one container into another container, and returning the prescribed semiconductor wafer transported into another container and subjected to the rework processing to the original one container. The storage apparatus stores one container and another container. The transfer apparatus transfers one container and another container to the manufacturing apparatus, the check apparatus, the storage apparatus and the wafer transport apparatus. The control apparatus controls the operations of the manufacturing apparatus, the check apparatus, the storage apparatus, the wafer transport apparatus and the transfer apparatus.
In accordance with this configuration, a determination result of the each semiconductor wafer by the check apparatus is stored by the control apparatus, and based on the check result, a semiconductor wafer determined as being failed is picked out from one container and transported into another container for forming a rework lot. Therefore the rework lot which is conventionally formed by the operator is formed timely and the container can be transferred efficiently. Furthermore, the manufacturing period can be shortened. In addition, the space for placing the container for the rework lot, which is required in the conventional check apparatus, needs not be provided in the check apparatus since the wafer transport apparatus transfers the semiconductor wafer determined as being failed from one container to another container. As a result, the serviceability ratio of the check apparatus can be improved and the area occupied by the check apparatus can be decreased.
According to another aspect of the present invention, a semiconductor device manufacturing line for manufacturing a semiconductor device using a container accommodating a semiconductor wafer has a plurality of containers, a storage apparatus, a wafer transport apparatus, a container cleaning apparatus, a transfer apparatus, and a control apparatus. A plurality of containers each accommodate a prescribed number of semiconductor wafers. The storage apparatus stores a plurality of containers. The wafer transport apparatus has a function of transporting a semiconductor wafer accommodated in one container among a plurality of containers to another container. The container cleaning apparatus cleans a plurality of containers. The transfer apparatus transfers each of a plurality of containers to the storage apparatus, the wafer transport apparatus and the container cleaning apparatus. The control apparatus includes functions of handling information regarding a container history including an elapsed time after cleaning by the container cleaning apparatus, the number of times of exchange and a purpose of use for each of plurality of containers, and of operating the storage apparatus, the wafer transport apparatus, the container cleaning apparatus and the transfer apparatus based on the information regarding the container history.
In accordance with this configuration, since the information regarding the container (carrier) history including an elapsed time after cleaning a container, a purpose of use and the number of times of use is handled by the control apparatus, it is easily determined whether a container emptied through the transport of the semiconductor wafer is reusable as an empty container. Therefore the cleaning of the empty container is appropriately limited based on the container history, as compared with the conventional carrier exchanging operation in which an empty container is cleaned each time it is emptied. As a result, it is less likely that the transfer of the container mounted with a semiconductor wafer and the transfer for the empty container affect each other due to the frequent transfer of the empty container, so that an efficient transfer can be realized. Furthermore, it is possible to reduce the unnecessary steps of cleaning an empty container, to minimize the number of cleaning apparatuses as required, and to cut down on the running cost for the cleaning step. In addition, the container is no longer cleaned frequently and the lifetime of the container can be prolonged.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.